Bill Mumy

Lennier (voice)

Real Dr. Smith

Dr. Zachary Smith

Self

Timothy Mccole

Ralph Waldo Pickle Chips

Agent Bryson (voice)

Major Keith

Harry Noze (voice)

Anthony Fremont

Paper Shredder Operator

Eon (voice)

Neighbor

Lennier

Kellin

Parker Craddick

The Farmer (voice)

The Fox (voice)

Bob

Roger Braintree

Young General Fleming

Dr. Irwin Bruckner

Tim

Art Barnes (uncredited)

Trask

Lariot

Custer

Will Robinson

Michael

David Taft

Child

Tony Mitchell

Willy

Jeffey

Billy Bayles

Anthony Fremont

Young Pip

Miles

Toddy

Little Boy at Carlton Hotel

Jackie Chester

Mickey Hollins

Little Boy Who Weighs Himself